Baffle insert for solid field combustion appliance

ABSTRACT

A baffle plate for use in a solid fuel combustion appliance having a solid fuel combustion chamber with a primary air inlet, and a primary combustion zone. The baffle plate located in the combustion chamber comprises at least one curved secondary air outlet chamber with a plurality of secondary air outlet openings located on it surface. Secondary air is then drawn into at least one secondary air inlet chamber that is fluidly connected to the at least one curved secondary air outlet chamber to provide air to the at least one curved secondary air outlet chamber where it is heated by the baffle plate and creates a secondary combustion zone within the combustion chamber.

This application claims priority to Australian Patent Application No. 2016900778, filed on 2 Mar. 2016, wherein the specification and contents of which is hereby incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

Embodiments of the invention generally relate to a baffle plate for use in a solid fuel heater. In particular, the invention relates to a battle plate having a plurality of air inlets disposed on a front surface that are in communication with a secondary air source so as to more efficiently and effectively combust the emissions from the combustion of material in a primary combustion zone in a heater.

Description of the Related Art

When wood, or other similar organic matter, burns in a slow combustion wood heater, it goes through several stages of combustion. During the pyrolysis stage as the cellulose matter changes to charcoal there is a lot of gases released otherwise known as smoke. To produce a low emission wood heater, these gases need to be burnt off so as to reduce the amount of smoke or un-combusted gaseous material from leaving the wood heater so as to reduce the heaters emissions.

Current wood heaters in the market have various methods of introducing oxygen into the gaseous combustion zone above the burning logs, otherwise known as secondary air. This is generally via a burn tube which is a 25-30 mm diameter tube extending from one side of the firebox to the other with a row of small holes introducing oxygen into the firebox. Primary air is often brought in at the front of the heater, down the glass and into the base of the fire.

Alternatively, or additionally depending on the model heater, additional oxygen is introduced via a row of holes in the rear of the firebox directly into the main combustion zone of the heater. In yet other examples, a catalytic converter is included into the baffle system with the aim of capturing and combating un-combusted products.

For combustion of the un-burnt gases to occur, the temperature must be 600-650° C. and additional oxygen should be introduced into the combustion chamber as this is typically an oxygen poor environment with most of it being used in the main combustion zone.

If the oxygen is not preheated sufficiently, as it enters the firebox it will lower the temperature and the gases will not ignite for complete combustion, resulting in the gases escaping through the flue thus increasing the heaters emissions.

BRIEF SUMMARY OF THE INVENTION

It is an object of one or more embodiments of the invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art.

Other objects and advantages of one or more embodiments of the invention will become apparent from the following description, taking in connection with the accompanying drawings, wherein, by way of illustration and example, at least one embodiment of the present invention is disclosed.

According to the present invention, although this should not be seen as limiting the invention in any way, in at least one embodiment there is provided a baffle plate for use in a solid fuel combustion appliance, the baffle plate having a main body section, the main body section having a front face and a back face, at least one curved secondary air outlet chambers having a plurality of secondary air outlet openings thereon and at least one secondary air inlet chamber fluidly connected to the at least one curved secondary air outlet chamber to provide air to the at least one curved secondary air outlet chamber.

In one or more embodiments, there are at least two curved secondary air outlet chambers.

In one or more embodiments, the at least two curved secondary air outlet chambers are substantially parallel with respect to each other.

In one or more embodiments, the curved secondary air outlet chambers are convex shaped.

In one or more embodiments, the curved secondary air outlet chambers have a convex face.

In one or more embodiments, the convex face is an outer face of the curved secondary air outlet chambers

In one or more embodiments, the plurality of secondary air outlet openings are located on a crest of the curved secondary air outlet chamber.

In one or more embodiments, the main body includes at least one secondary air inlet chamber.

In one or more embodiments, the secondary air inlet chamber is fluidly connected to at least one secondary air source.

In one or more embodiments, the at least one secondary air source is outside of the solid fuel combustion chamber.

In one or more embodiments, the secondary air inlet chamber is positioned on the back face of the main body section of the baffle plate.

In one or more embodiments, the curved secondary air outlet chambers are dome shaped.

In one or more embodiments, the curved secondary air outlet chambers are dimple shaped.

In one or more embodiments, the back face of the main body section has at least one opening thereon to allow fluid communication between the secondary air outlet chamber of the secondary air inlet chamber.

In one or more embodiments, a side face of the main body section has at least one opening thereon to allow fluid communication the secondary air inlet chamber between the secondary air outlet chamber of the secondary air inlet chamber.

In one or more embodiments of the invention there is a solid fuel combustion appliance having a baffle plate, the baffle plate having a main body section, the main body section having a front face and a back face, at least one curved secondary air outlet chambers having a plurality of secondary air outlet openings thereon and at least one secondary air inlet chamber fluidly connected to at least one curved secondary air outlet chamber to provide air to at least one curved secondary air outlet chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:

FIG. 1 is a front perspective view of the present invention;

FIG. 2 is a rear perspective view of the present invention;

FIG. 3 is a side view of the present invention;

FIG. 3a is further side view of the present invention with the side panel removed;

FIG. 4 is a rear view of the present invention;

FIG. 5 is a view of the front face of the present invention;

FIG. 6 is an alternative view of the front face of the present invention showing the back section;

FIG. 7 is rear view of the present invention;

FIG. 8 is a front perspective view with a removed curved secondary air outlet chamber to show an opening into the secondary air inlet chamber;

FIG. 9 is a rear perspective of FIG. 8 with the secondary air inlet chamber removed;

FIG. 10 is a perspective view of the curved secondary air outlet chambers of the present invention, with the main body section removed to show the interior;

FIG. 11 is a schematic view of the present invention in situ in a combustion appliance;

FIG. 12 is a side section view of the present invention showing the laminar air flow across its front face, noting a side panel of the secondary air inlet chamber has been removed for clarity.

DETAILED DESCRIPTION OF THE INVENTION

The baffle plate (10) has a main body section (15) with a front face (17) and a rear face (20). A front section (25) is in an angled relationship with the main body section (15) and extends substantially along the width of the front end of the baffle plate (10). At the rear end (30) of the baffle plate (10) is a back section (35), both the front section (25) and back section (35) may be formed integrally from a single plate of material suitable for use in a combustion appliance having a combustion chamber or alternatively they may be joined to the main body section (15) by way of welding or other suitable technique.

The back plate (35) has a number of fixing points (40) to allow the back plate (35) to be secured to a combustion appliance in the appropriate manner known to those skilled in this field.

Positioned on the front face (17) of the main body section (15) are curved secondary air outlet chambers (42) and (44) with side panels (43 a) and (43 b), each of which has secondary air outlet openings (45 a) positioned thereon. On the secondary air outlet chamber (42), the secondary air outlet openings (45 a) are arranged in a straight line travelling substantially parallel with the longitudinal edges (47) and (48) of the secondary air outlet chamber (42).

The number of secondary air outlet openings thereon the curved secondary air outlet chambers may be variable depending upon specific requirements such as the overall size of the solid fuel combustion appliance and the size of the baffle plate (10).

On the front section (25) there is a plurality of secondary outlet openings (45 c).

The baffle plate (10) further includes a secondary air inlet chamber (50) having a secondary air inlet opening (52) positioned on a rear end (54). An upwardly projecting flange (56) has an opening (58) to allow the option of further securing the baffle plate (10) to the solid fuel combustion chamber within which it resides.

The secondary air inlet chamber (50) is in fluid communication with a secondary air source that is external to the solid fuel combustion chamber so that at least the majority of the air entering into the secondary air inlet chamber (50) has a high level of oxygen compared to an interior of the solid fuel combustion chamber. The secondary air outlet chambers (42) and (44) are in direct communication with the secondary air inlet chamber (50) such that air entering into the inlet chamber (50) may then exit out through the openings (45 a, 45 b) on the outlet chambers (42) and (44) respectively.

In FIG. 8 the secondary air outlet chamber (44) has been removed to show the openings (51) through the main body section (15) that allows air in the secondary inlet chamber (50) to pass into the secondary air outlet chamber (44). Similar openings are provided for in relation to the other secondary air outlet chamber (42). The secondary inlet chamber (50) could also be manufactured so that there was openings (51) in the main body section, such as for example if the secondary inlet chamber integrated with the main body section, for example by press forming the secondary inlet chamber(s) from a single piece of sheet material.

In addition, the secondary air outlet openings (45) on the front section (25) may also be in fluid communication with the secondary air inlet chamber (50) to provide an additional input of air from the chamber (50) into the solid fuel combustion chamber. It is also considered within the scope of the present invention that the secondary air outlet holes may be connected to a separate secondary air inlet chamber if required, for example when additional airflow is required into the appliance.

The secondary air outlet chambers (42) and (44) are substantially convex in shape having a crest (46) located approximately equidistance from the parallel edges (47) and (48). The positioning of the row of secondary air outlet openings may be located closer to one edge than another, depending upon the final convex shape of the secondary air outlet chamber (42/44). The convex shape of the secondary air outlet chambers (42/44) may be substantially shaped like an aero foil or dome shaped or dimpled.

In use, the baffle plate (10) is positioned in the interior (100) of a solid fuel combustion appliance (110). The solid fuel (112) is ignited and creates a primary combustion zone (115). When the door (120) of the appliance (110) is closed outside air may enter by way of a top primary air control opening or inlet (125). The primary air entering via the top primary air control opening (125) is cooler than the air inside the combustion appliance and falls towards the bottom of the combustion chamber.

As the material (112) combusts, the resultant hot gases are lighter and travel upwards towards the baffle plate (10), which in turn is heated by the hot gases and the radiant heat from the primary combustion zone. The rising gases (140) travel upwards and over the secondary air outlet chambers (42/44) and as they pass over the secondary air openings (45) we have noted that this results in an increase of the velocity of the flow causing a decrease in pressure in the region adjacent to the secondary air openings (45) thus drawing in the secondary air from within the secondary air outlet chambers (42/44) through the openings (45). This is shown in FIG. 12 with the secondary air (135) entering into the baffle (10) through the opening (52) and shown as broken lines inside the secondary air inlet chamber (50). As the secondary air outlet chambers (42/44) are fluidly connected to the secondary air inlet chamber (50), which in turn is connected to an air inlet outside of the combustion chamber, a fresh source of air is thus brought into the combustion chamber and as it does so it is rapidly heated by way of the now hot baffle plate (10).

The shape and orientation of the secondary air outlet chambers (42) and (44) create a strong laminar airflow that until now has not been observed and the fresh secondary air (135) being brought in is then combusted which creates a secondary combustion zone (150). The laminar flow (130) along the front face (17) of the baffle plate (10) creates a substantial draw of secondary air and the newly created secondary combustion zone (150) provides an efficient means of combusting those as yet un-burnt gases/material from the primary combustion zone (115). In addition, flames may be visible in the secondary combustion zone (150) which add substantially to the visual effect overall from the combustion appliance.

The result of creating this efficient secondary combustion zone (150) is however that any un-burnt gases from the primary combustion zone are effectively and efficiently combusted in the secondary combustion zone (150) which therefore results in dramatic reduction of emissions from the combustion appliance compared to using a standard baffle system. The position and design of the secondary air outlet chambers that results in a laminar flow (130) over the front face (17) of the baffle plate (10) provides a strong draw of second air into the combustion chamber that until now has not been observed, at least not without the use of externally powered fans that force air into the appliance.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made within the scope of the invention, which is not to be limited to the details described herein but it is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus. 

What is claimed is:
 1. A baffle plate for use in a solid fuel combustion appliance having a solid fuel combustion chamber with a primary air inlet, a primary combustion zone, the baffle plate comprising: a main body section, the main body section comprising a front face and a back face, at least one curved secondary air outlet chamber having a plurality of secondary air outlet openings thereon, and at least one secondary air inlet chamber fluidly connected to the at least one curved secondary air outlet chamber to provide air to the at least one curved secondary air outlet chamber.
 2. The baffle plate of claim 1, wherein the at least one curved secondary air outlet chamber comprises at least two curved secondary air outlet chambers.
 3. The baffle plate of claim 2, wherein the at least two curved secondary air outlet chambers are substantially parallel with respect to each other.
 4. The baffle plate of claim 1, wherein the at least one curved secondary air outlet chamber has a convex face.
 5. The baffle plate of claim 4, wherein the convex face is an outer face of the at least one curved secondary air outlet chamber.
 6. The baffle plate of claim 1, wherein the plurality of secondary air outlet openings are located on a crest of the at least one curved secondary air outlet chamber.
 7. The baffle plate of claim 1, wherein the main body section includes at least one secondary air inlet chamber.
 8. The baffle plate of claim 7, wherein the at least one secondary air inlet chamber is fluidly connected to at least one secondary air source.
 9. The baffle plate of claim 8, wherein the at least one secondary air source is outside of the solid fuel combustion chamber.
 10. The baffle plate of claim 9, wherein the at least one secondary air inlet chamber is positioned on the back face of the main body section of the baffle plate.
 11. The baffle plate of claim 1, wherein each of the at least one curved secondary air outlet chamber is dome shaped.
 12. The baffle plate of claim 1, wherein each of the at least one curved secondary air outlet chamber is dimple shaped.
 13. The baffle plate of claim 10, wherein the back face of the main body section has at least one opening thereon to allow fluid communication between the at least one curved secondary air outlet chamber and the at least one secondary air inlet chamber.
 14. The baffle plate of claim 10, wherein the main body section further comprises a side face that has at least one opening thereon to allow fluid communication of the at least one secondary air inlet chamber between the at least one curved secondary air outlet chamber and the at least one secondary air inlet chamber.
 15. A solid fuel combustion appliance comprising: a solid fuel combustion chamber, and a baffle plate, the baffle plate comprising a main body section, wherein the main body section comprises a front face and a back face, at least one curved secondary air outlet chamber having a plurality of secondary air outlet openings thereon, and at least one secondary air inlet chamber fluidly connected to at least one curved secondary air outlet chamber to provide air to at least one curved secondary air outlet chamber. 